Multiplexer and method for driving the same

ABSTRACT

A multiplexer is provided herein. The multiplexer has a plurality of first driving units and a plurality of second driving units. Each of the first driving units has a first data voltage input terminal, and each of the second driving units has a second data voltage input terminal. The first data voltage input terminal and the second data voltage input terminal are configured to receive pixel voltage signals with different polarities. In the first driving unit, a voltage difference between a gate and a drain of a transistor is controlled by a first reset signal, wherein the transistor of the first driving unit is coupled to the first data voltage input terminal and a first data line. In the second driving unit, a voltage difference between a gate and a drain of a transistor is controlled by a second reset signal, wherein the transistor of the second driving unit is coupled to the second data voltage input terminal and a second data line.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.15/437,589, filed on Feb. 21, 2017 which is incorporated by referenceherein in its entirety claims and which claims priority to Taiwanapplication number 105105186, filed Feb. 22, 2016 the contents of whichare incorporated hereby by reference.

TECHNICAL FIELD

The present invention relates to a multiplexer and a method for drivingthe same, and specifically, to a multiplexer comprising single-typetransistors and a method for driving the same.

BACKGROUND ART

In the current display panel technology, because a low temperaturepoly-silicon (LTPS) thin film transistor (TFT) has a high mobility andhigh reliability, the panel can have a high aperture ratio, and acircuit of a multiplexer can be formed on a substrate, so as to reducethe number of source driver ICs, and satisfy high specification paneldesign requirements. In addition, during the operation of the panel,because a polarity reversal operation needs to be performed onsub-pixels of the panel, the polarity of a Gamma voltage received byeach of the sub-pixels in each frame period may be a positive polarityor a negative polarity. In the case where the polarity reversaloperation needs to be performed on the sub-pixels, a traditionalmultiplexer fabricated by using single-type transistors such as N-typemetal-oxide-semiconductor (NMOS) transistors or P-typemetal-oxide-semiconductor (PMOS) transistors may have different drivingcapabilities for the sub-pixels when receiving Gamma voltages ofdifferent polarities. Therefore, complementary metal oxide semiconductor(CMOS) transistors are traditionally adopted to produce the multiplexerin a display.

However, compared with a circuit using purely NMOS transistors or PMOStransistors, a circuit using CMOS transistors requires a relativelycomplicated process and a larger number of masks, causing a significantincrease in manufacturing costs of the panels fabricated with the CMOSprocess, which in turn is less welcome from the consumers' perspective.

SUMMARY OF THE INVENTION

In view of this, the present invention provides a new multiplexer and amethod for driving the same, so that the multiplexer has a sufficientdriving capability for data lines and sub-pixels no matter whether themultiplexer uses NMOS transistors or PMOS transistors.

One embodiment of the present invention provides a multiplexer. Themultiplexer includes a plurality of first driving units and a pluralityof second driving units. Each of the first driving units includes afirst data voltage input terminal, a first capacitor, a firsttransistor, and a second transistor. The first data voltage inputterminal is configured to receive a first pixel voltage signal. Thefirst capacitor includes a first terminal and a second terminal. Thefirst terminal of the first capacitor is configured to receive a firstswitch signal. The first transistor includes a first terminal coupled tothe second terminal of the first capacitor, a second terminal configuredto receive a first reset signal, and a control terminal configured toreceive a second switch signal. The first switch signal and the secondswitch signal have opposite phases. The second transistor includes afirst terminal coupled to the first data voltage input terminal, asecond terminal coupled to a first data line, and a control terminalcoupled to the second terminal of the first capacitor. Each of thesecond driving units includes a second data voltage input terminal, asecond capacitor, a third transistor, and a fourth transistor. Thesecond data voltage input terminal is configured to receive a secondpixel voltage signal, wherein the second pixel voltage signal and thefirst pixel voltage signal have opposite polarities. The secondcapacitor includes a first terminal and a second terminal. The firstterminal of the second capacitor is coupled to the first terminal of thefirst capacitor, and is configured to receive the first switch signal.The third transistor includes a first terminal coupled to the secondterminal of the second capacitor, a second terminal configured toreceive a second reset signal, and a control terminal coupled to thecontrol terminal of the first transistor to receive the second switchsignal. The fourth transistor includes a first terminal coupled to thesecond data voltage input terminal, a second terminal coupled to asecond data line, and a control terminal coupled to the second terminalof the second capacitor. The first reset signal is different from thesecond reset signal.

One embodiment of the present invention provides a multiplexer. Themultiplexer includes a plurality of first driving units and a pluralityof second driving units. Each of the first driving units includes afirst data voltage input terminal, a first transistor, a secondtransistor, a third transistor, a fourth transistor, and a firstcapacitor. The first data voltage input terminal is configured toreceive a first pixel voltage signal. The first transistor includes afirst terminal, a second terminal, and a control terminal. The firstterminal of the first transistor is configured to receive a first systemvoltage. The control terminal of the first transistor is configured toreceive a first switch signal. The second transistor includes a firstterminal coupled to the second terminal of the first transistor, asecond terminal configured to receive a second system voltage, and acontrol terminal configured to receive a second switch signal. The firstswitch signal and the second switch signal have opposite phases. Thethird transistor includes a first terminal, a second terminal, and acontrol terminal. The first terminal of the third transistor is coupledto the first data voltage input terminal, and the second terminal of thethird transistor is coupled to a first data line. The fourth transistorincludes a first terminal coupled to the control terminal of the thirdtransistor, a second terminal configured to receive a first resetsignal, and a control terminal configured to receive a second switchsignal. The first capacitor includes a first terminal coupled to thesecond terminal of the first transistor and the first terminal of thesecond transistor, and a second terminal coupled to the control terminalof the third transistor and the first terminal of the fourth transistor.Each of the second driving units includes a second data voltage inputterminal, a fifth transistor, a sixth transistor, a seventh transistor,an eighth transistor, and a second capacitor. The second data voltageinput terminal is configured to receive a second pixel voltage signal,wherein the second pixel voltage signal and the first pixel voltagesignal have opposite polarities. The fifth transistor includes a firstterminal, a second terminal, and a control terminal. The first terminalof the fifth transistor is configured to receive the first systemvoltage, and the control terminal of the fifth transistor is configuredto receive the first switch signal. The sixth transistor includes afirst terminal coupled to the second terminal of the fifth transistor, asecond terminal configured to receive the second system voltage, and acontrol terminal configured to receive the second switch signal. Theseventh transistor includes a first terminal, a second terminal, and acontrol terminal. The first terminal of the seventh transistor iscoupled to the second data voltage input terminal. The second terminalof the seventh transistor is coupled to the second data line. The eighthtransistor includes a first terminal coupled to the control terminal ofthe seventh transistor, a second terminal configured to receive thesecond reset signal, and a control terminal configured to receive thesecond switch signal. The second capacitor includes a first terminalcoupled to the second terminal of the fifth transistor and the firstterminal of the sixth transistor, and a second terminal coupled to thecontrol terminal of the seventh transistor and the first terminal of theeighth transistor. The first reset signal is different from the secondreset signal.

One embodiment of the present invention provides a method for drivingthe multiplexer described above. The multiplexer is used in a display,and all the transistors of the first driving unit and the second drivingunit are N-type metal-oxide-semiconductor transistors. The methodincludes: during the n^(th) frame period of the display, making thefirst pixel voltage signal to have a first polarity; making the secondpixel voltage signal to have a second polarity; making the first resetsignal to have an electric potential at a first reset level; and makingthe second reset signal to have an electric potential at a second resetlevel; wherein n is a positive integer, the first polarity is differentfrom the second polarity, and the second reset level is higher than thefirst reset level; and during the (n+1)^(th) frame period of thedisplay, making the first pixel voltage signal to have the secondpolarity, making the second pixel voltage signal to have the firstpolarity, making the first reset signal to have the electric potentialat the second reset level, and making the second reset signal to havethe electric potential at the first reset level.

One embodiment of the present invention provides a method for drivingthe multiplexer described above. The multiplexer is used in a display,and all the transistors of the first driving unit and the second drivingunit are P-type metal-oxide-semiconductor transistors. The methodincludes: during the n^(th) frame period of the display, making thefirst pixel voltage signal to have a first polarity; making the secondpixel voltage signal to have a second polarity; making the first resetsignal to have an electric potential at a first reset level; and makingthe second reset signal to have an electric potential at a second resetlevel; wherein n is a positive integer, the first polarity is differentfrom the second polarity, and the second reset level is higher than thefirst reset level; and during the (n+1)^(th) frame period of thedisplay, making the first pixel voltage signal to have the secondpolarity, making the second pixel voltage signal to have the firstpolarity, making the first reset signal to have the electric potentialat the second reset level, and making the second reset signal to havethe electric potential at the first reset level.

Through the embodiments of the present invention, two different resetsignals are applied to the multiplexer to increase an absolute value ofa voltage difference between a gate and a drain of a transistor fordriving a data line, thereby strengthening the driving capability of thetransistor. In this way, no matter whether the transistors of themultiplexer are NMOS transistors or PMOS transistors, the multiplexerhas a sufficient driving capability for data lines and sub-pixels.Therefore, all the transistors of the multiplexer can either be N-typemetal-oxide-semiconductor transistors or P-typemetal-oxide-semiconductor transistors, thereby simplifying the processof manufacturing the multiplexer and/or a panel and improving thecompetitiveness of products thereof.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 is a schematic diagram of a multiplexer applied to a displayaccording to an embodiment of the present invention.

FIG. 2 is a circuit diagram of two driving units for implementing themultiplexer in FIG. 1 according to an embodiment of the presentinvention.

FIG. 3 is a timing diagram of switch signals SWR, SWG, SWB, XSWR, XSWG,and XSWB in FIG. 2.

FIG. 4 is a timing diagram of a reset signal MUX_L1 and a reset signalMUX_L2 in FIG. 2.

FIG. 5 is a timing diagram of electric potentials of gates of thetransistors T2 and T4 in FIG. 2.

FIG. 6 is a circuit diagram of two driving units for implementing themultiplexer in FIG. 1 according to another embodiment of the presentinvention.

FIG. 7 is a timing diagram of switch signals SWR, SWG, SWB, XSWR, XSWG,and XSWB in FIG. 6.

FIG. 8 is a timing diagram of a reset signal MUX_L1 and a reset signalMUX_L2 in FIG. 6.

FIG. 9 is a timing diagram of electric potentials of gates of thetransistors T2 and T4 in FIG. 6.

FIG. 10 is a circuit diagram of two driving units for implementing themultiplexer in FIG. 1 according to another embodiment of the presentinvention.

FIG. 11 is a circuit diagram of two driving units for implementing themultiplexer in FIG. 1 according to another embodiment of the presentinvention.

FIG. 12 is a circuit diagram of two driving units for implementing themultiplexer in FIG. 1 according to an embodiment of the presentinvention.

FIG. 13 is a circuit diagram of two driving units for implementing themultiplexer in FIG. 1 according to another embodiment of the presentinvention.

FIG. 14 is a circuit diagram of two driving units for implementing themultiplexer in FIG. 1 according to another embodiment of the presentinvention.

FIG. 15 is a circuit diagram of the two driving units for implementingthe multiplexer in FIG. 1 according to another embodiment of the presentinvention.

DETAILED DESCRIPTIONS OF THE INVENTION

Please refer to FIG. 1. FIG. 1 is a schematic view of a multiplexer 100applied to a display 200 according to an embodiment of the presentinvention. The display 200 includes the multiplexer 100, red sub-pixelsR arranged in multiple columns, green sub-pixels G arranged in multiplecolumns, and blue sub-pixels B arranged in multiple columns, a pluralityof gate lines 210, and a plurality of data lines 220. Each red sub-pixelR, each green sub-pixel G, and each blue sub-pixel B are coupled to acorresponding gate line 210 and a corresponding data line 220. Themultiplexer 100 includes a plurality of driving units 110 and aplurality of driving units 120. The display 200 may be a liquid crystaldisplay, an electroluminescent display, electrowetting display, or anyother types of display.

Please refer to FIG. 2. FIG. 2 is a circuit diagram of two driving units110 and 120 for implementing the multiplexer in FIG. 1 according to anembodiment of the present invention. Each driving unit 110 includes adata voltage input terminal IN1, a capacitor C1, a transistor T1, and atransistor T2. The data voltage input terminal IN1 is configured toreceive a pixel voltage signal S1. The capacitor C1 includes a firstterminal and a second terminal, wherein the first terminal of thecapacitor C1 is configured to receive a switch signal SWR. Thetransistor T1 includes a first terminal coupled to the second terminalof the capacitor C1, a second terminal configured to receive a resetsignal MUX_L1, and a control terminal configured to receive a switchsignal XSWR. Each driving unit 120 includes a data voltage inputterminal IN2, a capacitor C2, a transistor T3, and a transistor T4. Thedata voltage input terminal IN2 is configured to receive a pixel voltagesignal S2. The capacitor C2 includes a first terminal and a secondterminal, wherein the first terminal of the capacitor C2 is configuredto receive the switch signal SWR. The transistor T3 includes a firstterminal coupled to the second terminal of the capacitor C1, a secondterminal configured to receive a reset signal MUX_L2, and a controlterminal configured to receive the switch signal XSWR. The reset signalMUX_L1 is different from the reset signal MUX_L2. The switch signal SWRand the switch signal XSWR have opposite phases. As shown in FIG. 3, theswitch signals SWR and XSWR are the respective square waves havingelectric potentials switched between a gate high potential VGH and agate low potential VGL, and the two signals have opposite phases. Thetransistor T2 includes a first terminal coupled to the data voltageinput terminal T1, a second terminal coupled to a data line L1, and acontrol terminal coupled to the second terminal of the capacitor C1. Inaddition, the data voltage input terminal IN2 is configured to receive apixel voltage signal S2, wherein the pixel voltage signal S2 and thepixel voltage signals S1 have opposite polarities. In other words, whenthe pixel voltage signal S1 has a positive polarity, the pixel voltagesignal S2 has a negative polarity; and when the pixel voltage signal S1has a negative polarity, the pixel voltage signal S2 has a positivepolarity. The transistor T4 includes a first terminal coupled to thedata voltage input terminal IN2, a second terminal coupled to a dataline L2, and a control terminal coupled to the second terminal of thecapacitor C2. In this embodiment, the transistors T1 to T4 are allN-type metal-oxide-semiconductor (NMOS) transistors.

Please refer to FIG. 2 to FIG. 3. FIG. 3 is a timing diagram of switchsignals SWR, SWG, SWB, XSWR, XSWG, and XSWB in FIG. 2. As shown in FIG.3, at intervals of a scan period H, the switch signal SWR is switchedfrom a gate low potential VGL to a gate high potential VGH, and then isswitched back from the gate high potential VGH to the gate low potentialVGL. Similarly, at intervals of the scan period H, the switch signalXSWR is switched from the gate high potential VGH to the gate lowpotential VGL, and then is switched back from the gate low potential VGLto the gate high potential VGH. Therefore, the switch signal SWR and theswitch signal XSWR have opposite phases. The scan period H is associatedwith a frame rate of the display 200 and the total number of gate lines210. Assuming that the frame rate of the display 200 is M frames persecond and the total number of the gate lines 210 of the display 200 isN, each scan period H is equal to 1/(M× N) seconds, and the switchsignals SWR, SWG, SWB, XSWR, XSWG, and XSWB generate N waveforms asshown in FIG. 3 in each frame period of the display 200; each scanperiod H corresponds to a scan time of one gate line 210.

Please refer to FIG. 2 to FIG. 5. FIG. 4 is a timing diagram of a resetsignal MUX_L1 and a reset signal MUX_L2 in FIG. 2, and FIG. 5 is atiming diagram of electric potentials of gates of the transistors T2 andT4 in FIG. 2. FIG. 4 and FIG. 5 show two frame periods F[+] and F[−] ofthe display 200, wherein the frame period F[+] represents that the pixelvoltage signal S1 or S2 applied to a certain sub-pixel of the display200 during the frame period F[+] has a positive polarity, and the frameperiod F[−] represents that the pixel voltage signal S1 or S2 applied toa certain sub-pixel of the display 200 during the frame period F[−] hasa negative polarity. For ease of description, sub-pixels coupled to thedata lines L1 and L2 in FIG. 2 are taken as an example for illustration.Whether the sub-pixel coupled to the data line L1 receives the pixelvoltage signal S1 from the data voltage input terminal IN1 depterminalson whether the transistor T2 is turned on; and whether the transistor T2is turned on depterminals on a bias of a gate of the transistor T2. Whenthe switch signal SWR is at the gate low potential VGL and the switchsignal XSWR is at the gate high potential VGH, because the transistor T1is turned on, the electric potential of the gate of the transistor T2 ispulled down to the electric potential of the reset signal MUX_L1, suchthat the transistor T2 is turned off; and the electrical connectionbetween the data voltage input terminal IN1 and the data line L1 is cutoff. In this case, the pixel voltage signal S1 will not be transmittedto the data line L1. On the contrary, when the switch signal SWR is atthe gate high potential VGH and the switch signal XSWR is at the gatelow potential VGL, the transistor T1 is not turned on, and the gate highpotential VGH of the switch signal SWR is applied to the gate of thetransistor T2 via a capacitor C1, such that the transistor T2 is turnedon. In this case, the electrical connection between the data voltageinput terminal IN1 and the data line L1 is established, such that thepixel voltage signal S1 is transmitted to the data line L1. Similarly,whether the sub-pixel coupled to the data line L2 receives the pixelvoltage signal S2 from the data voltage input terminal IN2 depterminalson whether the transistor T4 is turned on, and whether the transistor T4is turned on depterminals on the bias of the gate of the transistor T2.When the switch signal SWR is at the gate low potential VGL and theswitch signal XSWR is at the gate high potential VGH, because thetransistor T3 is turned on, the electric potential of the gate of thetransistor T4 is pulled down to the electric potential of the resetsignal MUX_L2, such that the transistor T4 is turned off, and theelectrical connection between the data voltage input terminal IN2 andthe data line L2 is cut off. In this case, the pixel voltage signal S2will not be transmitted to the data line L2. On the other hand, when theswitch signal SWR is at the gate high potential VGH and the switchsignal XSWR is at the gate low potential VGL, the transistor T3 is notturned on, and the gate high potential VGH of the switch signal SWR isapplied to the gate of the transistor T4 via the capacitor C2, such thatthe transistor T4 is turned on. In this case, the electrical connectionbetween the data voltage input terminal IN2 and the data line L2 isestablished, such that the pixel voltage signal S2 is transmitted to thedata line L2.

In addition, the waveforms of the switch signals SWR, SWG, SWB, XSWR,XSWG, and XSWB, for example, are not associated with the polarities ofthe sub-pixels. In other words, the waveforms of the switch signals SWR,SWG, SWB, XSWR, XSWG, and XSWB remain unchanged in different frameperiods F[+] and F[−]. However, the electric potential of the resetsignal MUX_L1, the electric potential of the reset signal MUX_L2, theelectric potential of the pixel voltage signal S2, and the electricpotential of the pixel voltage signal S2 are associated with thepolarities of the sub-pixels. For ease of description, it is assumedthat the electric potentials of the pixel voltage signal S1 during theframe periods F[+] and F[−] are equal to a positive polarity pixelvoltage +Vp and a negative polarity pixel voltage −Vp respectively; andthe electric potentials of the pixel voltage signal S2 during the frameperiods F[+] and F[−] are equal to the negative polarity pixel voltage−Vp and the positive polarity pixel voltage +Vp respectively, wherein Vpis greater than zero. In addition, as shown in FIG. 4, within the frameperiod F[+], the electric potential of the reset signal MUX_L1 is equalto a reset level Lv1, and the electric potential of the reset signalMUX_L2 is equal to a reset level Lv2; and within the frame period F[−],the electric potential of the reset signal MUX_L1 is equal to the resetlevel Lv2, and the electric potential of the reset signal MUX_L2 isequal to the reset level Lv1, wherein the reset level Lv2 is lower thanthe reset level Lv1. The setting principle of the reset levels Lv1 andLv2 is to smoothly turn off the transistor T2 when the transistor T1 isturned on, and to smoothly turn off the transistor T4 when thetransistor T3 is turned on. Therefore, the setting of the reset levelsLv1 and Lv2 is associated with the electric potentials of the voltageinput terminals IN1 and IN2. Specifically, when the transistor T1 isturned on and in order for the transistor T2 not to be turned on, theelectric potential of the voltage input terminal IN1 needs to be higherthan the electric potential of the MUX_L1. To this terminal, in theframe period F[+], the electric potential of the reset signal MUX_L1,equal to the reset level Lv1, needs to be lower than the electricpotential of the voltage input terminal IN1 (that is, the electricpotential of the pixel voltage signal S1); and in the frame period F[−],the electric potential of the reset signal MUX_L1, equal to the resetlevel Lv2, also needs to be lower than the electric potential of thevoltage input terminal IN1. In other words, assuming that the minimumelectric potentials of the pixel voltage signal S1 in the frame periodF[+] and the frame period F[−] are 0 V and −5 V respectively, the resetlevels Lv1 and Lv2 can be set to voltages below 0 V and −5 Vrespectively (for example, voltages of −1 V and −6 V). Similarly, whenthe transistor T3 is turned on and in order for the transistor T4 not tobe turned on, the electric potential of the voltage input terminal IN2needs to be higher than the electric potential of the MUX_L2. To thisterminal, in the frame period F[+], the electric potential of the resetsignal MUX_L2, equal to the reset level Lv2, needs to be lower than theelectric potential of the voltage input terminal IN2 (that is, theelectric potential of the pixel voltage signal S2); and in the frameperiod F[−], the electric potential of the reset signal MUX_L2, equal tothe reset level Lv1, also needs to be lower than the electric potentialof the voltage input terminal IN2. In other words, assuming that theminimum electric potentials of the pixel voltage signal S2 in the frameperiod F[−] and the frame period F[+] are 0 V and −5 V respectively, thereset levels Lv1 and Lv2 can be set to voltages below 0 V and −5 Vrespectively (for example, voltages of −1 V and −6 V), consistent withthe above inference. In this embodiment, the reset level Lv2 is the gatelow potential VGL. In another embodiment of the present invention, thereset level Lv1 is lower than a ground potential GND (that is, 0 V). Inanother embodiment of the present invention, a voltage differencebetween the ground potential GND and the reset level MUX_L1 is equal toa preset voltage difference, and the preset voltage difference isbetween Vth+0.5 V and Vth−0.5 V, wherein Vth is an average value ofthreshold voltages of all the transistors in the driving units 110 and120. According to another embodiment of the present invention, thepreset voltage difference may also be a threshold voltage of thetransistor T2 or the transistor T4.

During the frame period F[+], when the electric potential of the switchsignal SWR is equal to the gate low potential VGL, and the electricpotential of the switch signal XSWR is equal to the gate high potentialVGH, the transistors T1 and T3 are both turned on, such that the resetsignals MUX_L1 and MUX_L2 are transmitted to the gates of thetransistors T2 and T4 respectively. In this case, because the electricpotentials of the reset signals MUX_L1 and MUX_L2 are the reset levelsLv1 and Lv2 respectively, biases of the reset levels Lv1 and Lv2 areapplied to the respective gates of the transistors T2 and T4, so thatthe transistors T2 and T4 are not turned on. In this case, the voltagedifferences between the two terminals of the capacitor C1 and betweenthe two terminals of the capacitor C2 are (VGL−Lv1) and (VGL−Lv2)respectively. In FIG. 5, changes in the electric potentials of the gatesof the transistors T2 and T4 during the frame period F[+] are presentedthrough the respective curves 610 and 620. In addition, during the frameperiod F[+], when the electric potential of the switch signal SWR isequal to the gate high potential VGH, and the electric potential of theswitch signal XSWR is equal to the gate low potential VGL, thetransistors T1 and T3 are not turned on; yet the electric potential ofthe gate of the transistor T2 is increased to about (Lv1+VGH−VGL)because of the coupling effect of the capacitor C1, and the electricpotential of the gate of the transistor T4 is increased to about(Lv2+VGH−VGL) because of the coupling effect of the capacitor C2. As aresult, the transistors T2 and T4 are both turned on and the pixelvoltage signals S1 and S2 are transmitted to the data lines L1 and L2respectively; and the electric potentials of the data lines L1 and L2are the positive polarity pixel voltage +Vp and the negative polaritypixel voltage −Vp respectively. It is clear from the above descriptionthat when the transistors T2 and T4 are turned on because of thecoupling effect of the capacitors C1 and C2, the voltage differencesbetween the gate of the transistor T2 and the data line L1 and betweenthe gate of the transistor T4 and the data line L2 are (Lv1+VGH−VGL−Vp)and (Lv2+VGH−VGL+Vp) respectively. (Lv1+VGH−VGL−Vp) is equal to thevoltage difference ΔV1 shown in FIG. 5; and in the case where the resetlevel Lv2 is equal to the gate low potential VGL, (Lv2+VGH−VGL+Vp) isequal to (VGH+Vp) and is also equal to the voltage difference ΔV2Therefore, when the transistors T2 and T4 are turned on during the frameperiod F[+], the voltage differences between the gate and the drain ofthe transistor T2 and between the gate and the drain of the transistorT4 are equal to the voltage differences ΔV1 and ΔV2 respectively. Incomparison, if the switch signal SWR is directly transmitted to thegates of the transistors T2 and T4 without the coupling effect of thecapacitors C1 and C2, when the transistor T2 is turned on, the voltagedifference between the gate of the transistor T2 and the data line L1 isonly (VGH−Vp) (that is, ΔVa) during the frame period F[+], far less thanthe above (Lv1+VGH−VGL−Vp) (i.e., ΔV1). In other words, in thisembodiment, the voltage difference ΔV1 between the gate of thetransistor T2 and the data line L1 is greater than the voltagedifference ΔVa generated in a traditional driving manner; therefore,with the circuit structure and the driving manner of the aboveembodiment of the present invention, the transistors T1 to T4 still havesufficient driving capabilities for the data lines and the sub-pixels inthe case when the transistors T1 to T4 are all NMOS transistors.

Similarly, during the frame period F[−], when the electric potential ofthe switch signal SWR is equal to the gate low potential VGL, and theelectric potential of the switch signal XSWR is equal to the gate highpotential VGH, the transistors T1 and T3 are both turned on, such thatthe reset signals MUX_L1 and MUX_L2 are transmitted to the gates of thetransistors T2 and T4 respectively. In this case, because the electricpotentials of the reset signals MUX_L1 and MUX_L2 are the reset levelsLv2 and Lv1 respectively, biases of the reset levels Lv2 and Lv1 areapplied to the respective gates of the transistors T2 and T4, so thatthe transistors T2 and T4 are not turned on. In this case, voltage dropsbetween the two terminals of the capacitor C1 and between the twoterminals of the capacitor C2 are (VGL−Lv2) and (VGL−Lv1) respectively.In addition, during the frame period F[+], when the electric potentialof the switch signal SWR is equal to the gate high potential VGH, andthe electric potential of the switch signal XSWR is equal to the gatelow potential VGL, the transistors T1 and T3 are not turned on; yet theelectric potential of the gate of the transistor T2 is increased to(Lv2+VGH−VGL) because of the coupling effect of the capacitor C1, andthe electric potential of the gate of the transistor T4 is increased to(Lv1+VGH−VGL) because of the coupling effect of the capacitor C2. As aresult, the transistors T2 and T4 are both turned on and the pixelvoltage signals S1 and S2 are transmitted to the data lines L1 and L2respectively; and the electric potentials of the data lines L1 and L2are the negative polarity pixel voltage +Vp and the positive polaritypixel voltage −Vp respectively. It is clear from the above descriptionthat when the transistors T2 and T4 are turned on because of thecoupling effect of the capacitors C1 and C2, the voltage differencesbetween the gate of the transistor T2 and the data line L1 and betweenthe gate of the transistor T4 and the data line L2 are (Lv2+VGH−VGL+Vp)and (Lv1+VGH−VGL−Vp) respectively. (Lv1+VGH−VGL−Vp) is equal to thevoltage difference ΔV1 shown in FIG. 5; and in the case where the resetlevel Lv2 is equal to the gate low potential VGL, (Lv2+VGH−VGL+Vp) isequal to (VGH+Vp) and is also equal to the voltage difference ΔV2.Therefore, when the transistors T2 and T4 are turned on during the frameperiod F[−], the voltage differences between the gate and the drain ofthe transistor T2 and between the gate and the drain of the transistorT4 are equal to the voltage differences ΔV2 and ΔV1 respectively. Incomparison, if the switch signal SWR is directly transmitted to thegates of the transistors T2 and T4 without the coupling effect of thecapacitors C1 and C2, when the transistor T4 is turned on, the voltagedifference between the gate of the transistor T4 and the data line L2 isonly (VGH−Vp) (i.e., ΔVa) during the frame period F[−], far less thanthe above (Lv1+VGH−VGL−Vp) (i.e., ΔV1). In other words, in thisembodiment, the voltage difference ΔV1 between the gate of thetransistor T4 and the data line L2 is far greater than the voltagedifference ΔVa generated in a traditional driving manner; therefore,with the circuit structure and the driving manner of the aboveembodiment of the present invention, the transistors T1 to T4 still havesufficient driving capabilities for the data lines and the sub-pixels inthe case when the transistors T1 to T4 are all NMOS transistors.

Please refer to FIG. 2 and FIG. 3 again. In another embodiment of thepresent invention, each driving unit 110 may further include a capacitorC3, a transistor T5, a transistor T6, a capacitor C4, a transistor T7,and a transistor T8; and each driving unit 120 may further include acapacitor C5, a transistor T9, a transistor T10, a capacitor C6, atransistor T11, and a transistor T12. The capacitor C3 includes a firstterminal and a second terminal, wherein the first terminal of thecapacitor C3 is configured to receive the switch signal SWG. Thetransistor T5 includes a first terminal coupled to the second terminalof the third capacitor C3, a second terminal configured to receive thereset signal MUX_L1, and a control terminal configured to receive theswitch signal XSWG. The switch signal SWG and the switch signal XSWGhave opposite phases. The transistor T6 includes a first terminalcoupled to the data voltage input terminal IN1, a control terminalcoupled to the second terminal of the capacitor C3, and a secondterminal coupled to a data line L3. The capacitor C4 includes a firstterminal and a second terminal, wherein the first terminal of thecapacitor C4 is configured to receive the switch signal SWB. Thetransistor T7 includes a first terminal coupled to the second terminalof the capacitor C4, a second terminal configured to receive the resetsignal MUX_L1, and a control terminal configured to receive the switchsignal XSWB. The switch signal SWB and the switch signal XSWB haveopposite phases. The transistor T8 includes a first terminal coupled tothe data voltage input terminal IN1, a control terminal coupled to thesecond terminal of the capacitor C4, and a second terminal coupled to adata line L4. The capacitor C5 includes a first terminal and a secondterminal, wherein the first terminal of the capacitor C5 is coupled tothe first terminal of the capacitor C3, and is configured to receive theswitch signal SWG. The transistor T9 includes a first terminal coupledto the second terminal of the capacitor C5, a second terminal configuredto receive the reset signal MUX_L2, and a control terminal coupled tothe control terminal of the transistor T5 to receive the switch signalXSWG. The transistor T10 includes a first terminal coupled to the datavoltage input terminal IN2, a control terminal coupled to the secondterminal of the capacitor C5, and a second terminal coupled to a dataline L5. The capacitor C6 includes a first terminal and a secondterminal, wherein the first terminal of the capacitor C6 is coupled tothe first terminal of the capacitor C4, and is configured to receive theswitch signal SWB. The transistor T11 includes a first terminal coupledto the second terminal of the capacitor C6, a second terminal configuredto receive the reset signal MUX_L2, and a control terminal coupled tothe control terminal of the transistor T7 to receive the switch signalXSWB. The transistor T12 includes a first terminal coupled to the datavoltage input terminal IN2, a control terminal coupled to the secondterminal of the capacitor C6, and a second terminal coupled to a dataline L6.

In this embodiment, the transistors T1 to T12 are all NMOS transistors.The operation manner of the capacitor C3, the transistor T5, and thetransistor T6 of the driving unit 110 is similar to that of thecapacitor C1, the transistor T1, and the transistor T2; and theoperation manner of the capacitor C5, the transistor T9, and thetransistor T10 of the driving unit 120 is similar to that of thecapacitor C2, the transistor T3, and the transistor T4. What isdifferent is that the operations of the capacitor C1, the transistor T1,and the transistor T2 and the operations of the capacitor C2, thetransistor T3, and the transistor T4 are controlled by the switchsignals SWR and XSWR, whereas the operations of the capacitor C3, thetransistor T5, and the transistor T6 and the operations of the capacitorC5, the transistor T9, and the transistor T10 are controlled by theswitch signals SWG and XSWG instead. The rest of the operation mannersremain the same. As shown in FIG. 3, the switch signals SWG and XSWGmerely slightly lag behind the switch signals SWR and XSWR in terms ofthe time sequence, and the switch signals SWR and SWG are the gate highpotential VGH at different times. Therefore, both the operation mannersof the capacitor C3, the transistor T5, and the transistor T6 of thedriving unit 110, and of the capacitor C5, the transistor T9, and thetransistor T10 of the driving unit 120 can be inferred by referring tothe aforementioned operation manner of the capacitor C1, the transistorT1, and the transistor T2, and the aforementioned operation manner ofthe capacitor C2, the transistor T3, and the transistor T4. Details arenot described again herein.

Likewise, the operation manner of the capacitor C4, the transistor T7,and the transistor T8 of the driving unit 110 is similar to that of thecapacitor C1, the transistor T1, and the transistor T2; and theoperation manner of the capacitor C6, the transistor T11, and thetransistor T12 of the driving unit 120 is similar to that of thecapacitor C2, the transistor T3, and the transistor T4. What isdifferent is that the operations of the capacitor C1, the transistor T1,and the transistor T2 and the operations of the capacitor C2, thetransistor T3, and the transistor T4 are controlled by the switchsignals SWR and XSWR, whereas the operations of the capacitor C4, thetransistor T7, and the transistor T8 and the operations of the capacitorC6, the transistor T11, and the transistor T12 are controlled by theswitch signals SWB and XSWB instead. The rest of the operation mannersremain the same. As shown in FIG. 3, the switch signals SWB and XSWBmerely slightly lag behind the switch signals SWR and XSWR in terms ofthe time sequence, and the switch signals SWR, SWG, and SWB are the gatehigh potential VGH at different times. Thus, both the operation mannersof the capacitor C4, the transistor T7, and the transistor T8 of thedriving unit 110, and of the capacitor C6, the transistor T11, and thetransistor T12 of the driving unit 120 can be inferred by referring tothe aforementioned operation manner of the capacitor C1, the transistorT1, and the transistor T2 and the aforementioned operation manner of thecapacitor C2, the transistor T3, and the transistor T4. Details are notdescribed again herein.

In an embodiment of the present invention, the data lines L1, L2, L3,L4, L5, and L6 are coupled to the sub-pixels including a red sub-pixelR, a green sub-pixel G, a blue sub-pixel B, a red sub-pixel R, a greensub-pixel G, and a blue sub-pixel B respectively. Because the pixelvoltage signals S1 and S2 received by the data voltage input terminalsIN1 and IN2 have different polarities, the display 200 is driven in acolumn inversion manner through the above circuit structure andconnection manner.

In an embodiment of the present invention, the transistors T1 to T12 areall PMOS transistors. As shown in FIG. 6, a circuit diagram of twodriving units 110 and 120 for implementing the multiplexer in FIG. 1according to another embodiment of the present invention, wherein thetransistors T1 to T12 are implemented by using PMOS transistors instead.To accommodate the changes of using PMOS transistors in implementing thetransistors T1 to T12, the waveforms of the switch signals SWR, SWG,SWB, XSWR, XSWG, and XSWB and the waveforms of the reset signals MUX_L1and MUX_L2 should be changed accordingly. Please refer to FIG. 7 to FIG.9. FIG. 7 is a timing diagram of switch signals SWR, SWG, SWB, XSWR,XSWG, and XSWB in FIG. 6; FIG. 8 is a timing diagram of a reset signalMUX_L1 and a reset signal MUX_L2 in FIG. 6; and FIG. 9 is a timingdiagram of electric potentials of gates of the transistors T2 and T4 inFIG. 6. At intervals of a scan period H, the switch signals SWR, SWG,and SWB are switched in sequence from the gate high potential VGH to thegate low potential VGL, and then switched back in sequence from the gatelow potential VGL to the gate high potential VGH. Similarly, atintervals of the scan period H, the switch signals XSWR, XSWG, and XSWBare switched in sequence from the gate low potential VGL to the gatehigh potential VGH, and then switched back in sequence from the gatehigh potential VGH to the gate low potential VGL. In addition, withinthe frame period F[±], the electric potential of the reset signal MUX_L1is equal to a reset level Lv4, and the electric potential of the resetsignal MUX_L2 is equal to a reset level Lv3; and within the frame periodF[−], the electric potential of the reset signal MUX_L1 is equal to thereset level Lv3, and the electric potential of the reset signal MUX_L2is equal to the reset level Lv4, wherein the reset level Lv4 is higherthan the reset level Lv3. In this embodiment, the reset level Lv4 is thegate high potential VGH. In another embodiment of the present invention,the reset level Lv3 is higher than a ground potential GND. In anotherembodiment of the present invention, a voltage difference between thereset level MUX_L1 and the ground potential GND is equal to a presetvoltage difference, and the above preset voltage difference is betweenVth+0.5 V and Vth−0.5 V, wherein Vth is an average value of the absolutevalues of threshold voltages of all the transistors of the driving units110 and 120.

During the frame period F[+], when the electric potential of the switchsignal SWR is equal to the gate high potential VGH, and the electricpotential of the switch signal XSWR is equal to the gate low potentialVGL, the transistors T1 and T3 in FIG. 6 are both turned on, such thatthe reset signals MUX_L1 and MUX_L2 are transmitted to the gates of thetransistors T2 and T4 respectively. In this case, because the electricpotentials of the reset signals MUX_L1 and MUX_L2 are the reset levelsLv4 and Lv3 respectively, biases of the reset levels Lv4 and Lv3 areapplied to the respective gates of the transistors T2 and T4, so thatthe transistors T2 and T4 are not turned on. In this case, the voltagedrops between the two terminals of the capacitor C1 and between the twoterminals of the capacitor C2 are (VGH−Lv4) and (VGH−Lv3) respectively.In addition, during the frame period F[+], when the electric potentialof the switch signal SWR is equal to the gate low potential VGL, and theelectric potential of the switch signal XSWR is equal to the gate highpotential VGH, the transistors T1 and T3 are not turned on; yet theelectric potential of the gate of the transistor T2 is decreased to(Lv4−VGH+VGL) because of the coupling effect of the capacitor C1, andthe electric potential of the gate of the transistor T4 is decreased to(Lv3−VGH+VGL) because of the coupling effect of the capacitor C2. As aresult, the transistors T2 and T4 are both turned on and the pixelvoltage signals S1 and S2 are transmitted to the data lines L1 and L2respectively; and the electric potentials of the data lines L1 and L2are the positive polarity pixel voltage +Vp and the negative polaritypixel voltage −Vp respectively. It is clear from the above descriptionthat when the transistors T2 and T4 are turned on because of thecoupling effect of the capacitors C1 and C2, the voltage differencesbetween the drain and the gate of the transistor T2 and between thedrain and the gate of the transistor T4 are (Vp−Lv4+VGH−VGL) and(−Vp−Lv3+VGH−VGL) respectively. (−Vp−Lv3+VGH−VGL) is equal to thevoltage difference ΔV4 in FIG. 9; and in the case where the reset levelLv4 is the gate high potential VGH, (Vp−Lv4+VGH−VGL) is equal to(Vp−VGL) and is also equal to the voltage difference ΔV3. Therefore,when the transistors T2 and T4 are turned on during the frame periodF[+], the voltage difference between the drain and the gate of thetransistor T2 is equal to ΔV3, and the voltage difference between thedrain and the gate of the transistor T4 is equal to ΔV4. In comparison,if the switch signal SWR is directly transmitted to the gates of thetransistors T2 and T4 without the coupling effect of the capacitors C1and C2, when the transistor T4 is turned on, the voltage differencebetween the drain and the gate thereof is only (−Vp−VGL) (i.e., ΔVb)during the frame period F[+], far less than the above (−Vp−Lv3+VGH−VGL)(i.e., ΔV4). In other words, in this embodiment, the voltage differenceΔV4 between the drain and the gate of the transistor T4 is far greaterthan the voltage difference ΔVb generated in a traditional drivingmanner; therefore, with the circuit structure and the driving manner ofthe above embodiment of the present invention, the transistors T1 to T4still have sufficient driving capabilities for the data lines and thesub-pixels in the case when the transistors T1 to T4 are all PMOStransistors.

Similarly, during the frame period F[−], when the electric potential ofthe switch signal SWR is equal to the gate high potential VGH, and theelectric potential of the switch signal XSWR is equal to the gate lowpotential VGL, the transistors T1 and T3 in FIG. 6 are both turned on,such that the reset signals MUX_L1 and MUX_L2 are transmitted to thegates of the transistors T2 and T4 respectively. In this case, becausethe electric potentials of the reset signals MUX_L1 and MUX_L2 are resetlevels Lv3 and Lv4 respectively, biases of the reset levels Lv3 and Lv4are applied to the respective gates of the transistors T2 and T4, sothat the transistors T2 and T4 are not turned on. In this case, thevoltage drops between the two terminals of the capacitor C1 and betweenthe two terminals of the capacitor C2 are (VGH−Lv3) and (VGL−Lv4)respectively. In addition, during the frame period F[−], when theelectric potential of the switch signal SWR is equal to the gate lowpotential VGL, and the electric potential of the switch signal XSWR isequal to the gate high potential VGH, the transistors T1 and T3 are notturned on; yet the electric potential of the gate of the transistor T2is decreased to (Lv4−VGH+VGL) because of the coupling effect of thecapacitor C1, and the electric potential of the gate of the transistorT4 is increased to (Lv3−VGH+VGL) because of the coupling effect of thecapacitor C2. As a result, the transistors T2 and T4 are both turned onand the pixel voltage signals S1 and S2 are transmitted to the datalines L1 and L2 respectively; and the electric potentials of the datalines L1 and L2 are the negative polarity pixel voltage −Vp and thepositive polarity pixel voltage +Vp respectively. It is clear from theabove description that when the transistors T2 and T4 are turned onbecause of the coupling effect of the capacitors C1 and C2, the voltagedifferences between the drain and the gate of the transistor T2 andbetween the drain and the gate of the transistor T4 are (Vp−Lv4+VGH−VGL)and (−Vp−Lv3+VGH−VGL) respectively, which are equal to the respectivevoltage differences ΔV4 and ΔV3. In comparison, if the switch signal SWRis directly transmitted to the gates of the transistors T2 and T4without the coupling effect of the capacitors C1 and C2, when thetransistor T2 is turned on, the voltage difference between the drain andthe gate thereof is only (−Vp−VGL) (i.e., ΔVb) during the frame periodF[−], far less than the above (−Vp−Lv3+VGH−VGL) (i.e., ΔV4). In otherwords, in this embodiment, the voltage difference ΔV4 between the drainand the gate of the transistor T2 is far greater than the voltagedifference ΔVb generated in a traditional driving manner; therefore,with the circuit structure and the driving manner of the aboveembodiment of the present invention, the transistors T1 to T4 still havesufficient driving capabilities for the data lines and the sub-pixels inthe case when the transistors T1 to T4 are all PMOS transistors.

When the transistors T1 to T12 are all PMOS transistors, both theoperation manners of the capacitor C3, the transistor T5, and thetransistor T6 of the driving unit 110, and of the capacitor C4, thetransistor T7, and the transistor T8 of the driving unit 110 can beinferred by referring to the above operation manner of the capacitor C1,the transistor T1, and the transistor T2 in FIG. 6. In addition, boththe operation manners of the capacitor C5, the transistor T9, and thetransistor T10 of the driving unit 110, and of the capacitor C6, thetransistor T11, and the transistor T12 of the driving unit 110 can beinferred by referring to the above operation manner of the capacitor C1,the transistor T1, and the transistor T2 in FIG. 6. Details are notdescribed again herein.

In an embodiment of the present invention, the driving unit 110 and thedriving unit 120 of the multiplexer 100 may be integrated with a celltesting (CT) circuit of the display 200. Please refer to FIG. 10. FIG.10 is a circuit diagram of two driving units 110 and 120 forimplementing the multiplexer in FIG. 1 according to another embodimentof the present invention. Compared with the driving units 110 and 120 inFIG. 2, the driving unit 110 in FIG. 10 further includes a transistorT13, and the driving unit 120 in FIG. 10 further includes a transistorT14. The transistors T13 and T14 are both NMOS transistors. Thetransistor T13 includes a first terminal configured to receive theswitch signal SWR, a second terminal coupled to the data line L1, and acontrol terminal configured to receive a test control signal CT. Thetransistor T14 includes a first terminal configured to receive theswitch signal SWR, a second terminal coupled to the data line L2, and acontrol terminal configured to receive a test control signal CT. When acell testing is performed on the display 200, the electric potential ofthe test control signal CT is increased to a high electric potential, sothat the transistors T13 and T14 are turned on to transmit the switchsignal SWR to the data lines L1 and L2. Meanwhile, the transistors T1and T3 are turned on because of the switch signal XSWR, such that thetransistors T2 and T4 are turned off because the biases of the resetsignals MUX_L1 and MUX_L2 are being applied to the gates thereof; andduring a normal period in which a cell testing is not performed, theelectric potential of the test control signal CT is a low electricpotential, so that the transistors T13 and T14 are not turned on. As aresult, when a cell testing is performed on the display 200, the switchsignal SWR is used as a pixel voltage signal to update the gray level ofthe sub-pixels of the display 200.

In another embodiment of the present invention, the driving unit 110further includes transistors T13, T15, and T16, and the driving unit 120further includes transistors T14, T17, and T18. The transistors T13 toT18 are all NMOS transistors. The transistor T13 includes a firstterminal configured to receive the switch signal SWR, a second terminalcoupled to the data line L1, and a control terminal configured toreceive the test control signal CT. The transistor T14 includes a firstterminal configured to receive the switch signal SWR, a second terminalcoupled to the data line L2, and a control terminal configured toreceive the test control signal CT. The transistor T15 includes a firstterminal configured to receive the switch signal SWG, a second terminalcoupled to a data line L3, and a control terminal configured to receivethe test control signal CT. The transistor T16 includes a first terminalconfigured to receive the switch signal SWB, a second terminal coupledto a data line L4, and a control terminal configured to receive the testcontrol signal CT. The transistor T17 includes a first terminalconfigured to receive the switch signal SWG, a second terminal coupledto a data line L5, and a control terminal configured to receive the testcontrol signal CT. The transistor T18 includes a first terminalconfigured to receive the switch signal SWB, a second terminal coupledto a data line L6, and a control terminal configured to receive the testcontrol signal CT. When a cell testing is performed on the display 200,the electric potential of the test control signal CT is increased to ahigh electric potential, so that the transistors T13 and T18 are turnedon to transmit the switch signal SWR to the data lines L1 and L2,transmit the switch signal SWG to the data lines L3 and L4, and transmitthe switch signal SWB to the data lines L5 and L6. Meanwhile, thetransistors T1, T3, T5, T7, T9, and T11 are turned on because of theswitch signals XSWR, XSWG, and/or XSWB, such that the transistors T2,T4, T6, T8, T10, and T12 are turned off because the biases of the resetsignals MUX_L1 and/or MUX_L2 are being applied to the gates thereof. Inother words, when a cell testing is performed on the display 200, theswitch signals SWR, SWG, and SWB are used as pixel voltage signals toupdate the gray level of the sub-pixels of the display 200. In addition,it should be noted that when a cell testing is performed on the display200, data voltage input terminals IN1 and IN2 stop inputting the pixelvoltage signals S1 and S2, so that any interference to the cell testingprocess can be avoided.

In an embodiment of the present invention, the transistors T1 to T18 inFIG. 10 may be implemented by using PMOS transistors instead. Pleaserefer to FIG. 11, a circuit diagram of two driving units 110 and 120 forimplementing the multiplexer in FIG. 1 according to another embodimentof the present invention. The difference between the driving units 110and 120 in FIG. 11 and those in FIG. 10 is that all the transistors, T1to T18, of the driving units 110 and 120 in FIG. 11 are PMOStransistors. When a cell testing is performed on the display 200, theelectric potential of the test control signal CT is increased to a lowelectric potential, so that the transistors T13 and T18 are turned on totransmit the switch signal SWR to the data lines L1 and L2, transmit theswitch signal SWG to the data lines L3 and L4, and transmit the switchsignal SWB to the data lines L5 and L6.

Please refer to FIG. 12. FIG. 12 is a circuit diagram of two drivingunits 110 and 120 for implementing the multiplexer in FIG. 1 accordingto an embodiment of the present invention. Each driving unit 110includes a data voltage input terminal IN1, a transistor T1, atransistor T2, a transistor T3, a transistor T4, and a capacitor C1. Thedriving unit 120 includes a data voltage input terminal IN2, atransistor T5, a transistor T6, a transistor T7, a transistor T8, and acapacitor C2. The data voltage input terminal IN1 is configured toreceive a pixel voltage signal S1. The transistor T1 includes a firstterminal, a second terminal, and a control terminal. The first terminalof the transistor T1 is configured to receive a system voltage VDD. Thecontrol terminal of the transistor T1 is configured to receive a switchsignal SWR. The system voltage VDD is a positive voltage (for example, 5V, 3 V, or a gate high voltage VGH, etc.). The transistor T2 includes afirst terminal coupled to the second terminal of the transistor T1, asecond terminal configured to receive a system voltage VSS, and acontrol terminal configured to receive a switch signal XSWR. The switchsignal SWR and the switch signal XSWR have opposite phases. The systemvoltage VSS is lower than the system voltage VDD, and may be, forexample, a ground potential (i.e., 0 V) or a gate low voltage VGL. Thetransistor T3 includes a first terminal, a second terminal, and acontrol terminal. The first terminal of the transistor T3 is coupled tothe data voltage input terminal IN1, and the second terminal of thetransistor T3 is coupled to a first data line. The transistor T4includes a first terminal coupled to the control terminal of thetransistor T3, a second terminal configured to receive a reset signalMUX_L1, and a control terminal configured to receive the switch signalXSWR. The capacitor C1 includes a first terminal coupled to the secondterminal of the transistor T1 and the first terminal of the transistorT2, and a second terminal coupled to the control terminal of thetransistor T3 and the first terminal of the transistor T4. A datavoltage input terminal IN2 is configured to receive a pixel voltagesignal S2, wherein the pixel voltage signal S2 and the pixel voltagesignals S1 have opposite polarities. The transistor T5 includes a firstterminal, a second terminal, and a control terminal. The first terminalof the transistor T5 is configured to receive the system voltage VDD,and the control terminal of the transistor T5 is configured to receivethe switch signal SWR. The transistor T6 includes a first terminalcoupled to the second terminal of the transistor T5, a second terminalconfigured to receive a system voltage VSS, and a control terminalconfigured to receive a switch signal XSWR. The transistor T7 includes afirst terminal, a second terminal, and a control terminal. The firstterminal of the transistor T7 is coupled to the data voltage inputterminal IN2. The second terminal of the transistor T7 is coupled to asecond data line. The transistor T8 includes a first terminal coupled tothe control terminal of the transistor T7, a second terminal configuredto receive a reset signal MUX_L2, and a control terminal configured toreceive the switch signal XSWR. The capacitor C2 includes a firstterminal coupled to both the second terminal of the transistor T5 andthe first terminal of the transistor T6, and a second terminal coupledto both the control terminal of the transistor T7 and the first terminalof the transistor T8. The reset signal MUX_L1 is different from thereset signal MUX_L2. In this embodiment, a timing diagram of the switchsignals SWR, SWG, SWB, XSWR, XSWG, and XSWB is FIG. 3; a timing diagramof the reset signals MUX_L1 and MUX_L2 is FIG. 4; and the transistors T1to T8 are all NMOS transistors.

Please refer to FIG. 12 and FIG. 3 to FIG. 5. During the frame periodF[+], when the electric potential of the switch signal SWR is equal tothe gate low potential VGL, and the electric potential of the switchsignal XSWR is equal to the gate high potential VGH, neither thetransistor T1 or the transistor T5 is turned on, but the transistors T2,T4, T6, and T8 are all turned on, such that the system voltage VSS istransmitted to the first terminals of the capacitors C1 and C2, and thereset signals MUX_L1 and MUX_L2 are transmitted to the gates of thetransistors T4 and T8 respectively. In this case, because the electricpotentials of the reset signals MUX_L1 and MUX_L2 are the reset levelsLv1 and Lv2 respectively, biases of the reset levels Lv1 and Lv2 areapplied to the respective gates of the transistors T3 and T7, so thatthe transistors T3 and T7 are not turned on. In this case, the voltagedrops between the two terminals of the capacitor C1 and between the twoterminals of the capacitor C2 are (VSS−Lv1) and (VSS−Lv2) respectively.In addition, during the frame period F[+], when the electric potentialof the switch signal SWR is equal to the gate high potential VGH, andthe electric potential of the switch signal XSWR is equal to the gatelow potential VGL, the transistors T1 and T5 are both turned on, whereasnone of the transistors T2, T4, T6, and T8 is turned on, such that thesystem voltage VDD is transmitted to the first terminals of thecapacitors C1 and C2. In this case, the electric potential of the gateof the transistor T3 is increased to (Lv1+VDD−VSS) because of thecoupling effect of the capacitor C1, and the electric potential of thegate of the transistor T7 is increased to (Lv2+VDD−VSS) because of thecoupling effect of the capacitor C2. As a result, the transistors T3 andT7 are both turned on and the pixel voltage signals S1 and S2 aretransmitted to the data lines L1 and L2 respectively; and the electricpotentials of the data lines L1 and L2 are the positive polarity pixelvoltage +Vp and the negative polarity pixel voltage −Vp respectively. Itis clear from the above description that, when the transistors T3 and T7are turned on because of the coupling effect of the capacitors C1 andC2, the voltage differences between the gate of the transistor T3 andthe data line L1 and between the gate of the transistor T7 and the dataline L2 are (Lv1+VDD−VSS−Vp) and (Lv2+VDD−VSS+Vp) respectively. Incomparison, if the switch signal SWR is directly transmitted to thegates of the transistors T3 and T7 without the coupling effect of thecapacitors C1 and C2, when the transistor T3 is turned on, the voltagedifference between the gate of the transistor T3 and the data line L1 isonly (VGH−Vp) (i.e., ΔVa) during the frame period F[+]; and in the casewhere the difference between the system voltages VDD and VSS is greatenough, the voltage difference ΔVa will be far less than the above(Lv1+VDD−VSS−Vp). In other words, in this embodiment, the voltagedifference (Lv1+VDD−VSS−Vp) between the gate of the transistor T3 andthe data line L1 is far greater than the voltage difference ΔVagenerated in a traditional driving manner; therefore, with the circuitstructure and the driving manner of the above embodiment of the presentinvention, the transistors T1 to T8 still have sufficient drivingcapabilities for the data lines and the sub-pixels in the case when thetransistors T1 to T8 are all NMOS transistors.

Similarly, during the frame period F[−], when the electric potential ofthe switch signal SWR is equal to the gate low potential VGL, and theelectric potential of the switch signal XSWR is equal to the gate highpotential VGH, neither the transistor T1 or the transistor T5 in FIG. 12is turned on, but the transistors T2, T4, T6, and T8 are all turned on,such that the system voltage VSS is transmitted to the first terminalsof the capacitors C1 and C2, and the reset signals MUX_L1 and MUX_L2 aretransmitted to the gates of the transistors T4 and T8 respectively. Inthis case, because the electric potentials of the reset signals MUX_L1and MUX_L2 are the reset levels Lv2 and Lv1 respectively, biases of thereset levels Lv1 and Lv2 are applied to the respective gates of thetransistors T3 and T7, so that the transistors T3 and T7 are not turnedon. In this case, the voltage drops between two terminals of thecapacitor C1 and between two terminals of the capacitor C2 are equal to(VSS−Lv2) and (VSS−Lv1), respectively. In addition, when the electricpotential of the switch signal SWR is equal to the gate high potentialVGH, and the electric potential of the switch signal XSWR is equal tothe gate low potential VGL, both the transistors T1 and T5 are turnedon, whereas none of the transistors T2, T4, T6, and T8 is turned on,such that the system voltage VDD is transmitted to the first terminalsof the capacitors C1 and C2; the electric potential of the gate of thetransistor T3 is increased to (Lv2+VDD−VSS) because of the couplingeffect of the capacitor C1, and the electric potential of the gate ofthe transistor T4 is increased to (Lv1+VDD−VSS) because of the couplingeffect of the capacitor C2. As a result, both the transistors T3 and T7are turned on and the pixel voltage signals S1 and S2 are transmitted tothe data lines L1 and L2 respectively; and the electric potentials ofthe data lines L1 and L2 are the negative polarity pixel voltage −Vp andthe positive polarity pixel voltage +Vp respectively. It is clear fromthe above description that, when the transistors T3 and T7 are turned onbecause of the coupling effect of the capacitors C1 and C2, the voltagedifferences between the gate of the transistor T3 and the data line L1and between the gate of the transistor T7 and the data line L2 are(Lv2+VDD− VSS+Vp) and (Lv1+VDD− VSS−Vp) respectively. In comparison, ifthe switch signal SWR is directly transmitted to the gates of thetransistors T3 and T7 without the coupling effect of the capacitors C1and C2, when the transistor T7 is turned on, the voltage differencebetween the gate of the transistor T7 and the data line L2 is only(VGH−Vp) (i.e., ΔVa) during the frame period F[−]; and in the case wherethe difference between the system voltages VDD and VSS is great enough,the voltage difference ΔVa will be far less than the above (Lv1+VDD−VSS−Vp). In other words, in this embodiment, the voltage difference(Lv1+VDD− VSS−Vp) between the gate of the transistor T7 and the dataline L2 may be far greater than the voltage difference ΔVa generated ina traditional driving manner; therefore, with the circuit structure andthe driving manner of the above embodiment of the present invention, thetransistors T1 to T8 still have sufficient driving capabilities for thedata lines and the sub-pixels in the case when the transistors T1 to T8are all NMOS transistors.

With reference to FIG. 12 and FIG. 3, in another embodiment of thepresent invention, each driving unit 110 in FIG. 12 may further includetransistors T9 to T12, a capacitor C3, transistors T13 to T16, and acapacitor C4; and each driving unit 120 may further include transistorsT17 to T20, a capacitor C5, transistors T21 to T24, and a capacitor C6.The transistor T9 includes a first terminal configured to receive asystem voltage VDD, a second terminal, and a control terminal configuredto receive a switch signal SWG. The transistor T10 includes a firstterminal coupled to the second terminal of the transistor T9, a secondterminal configured to receive a system voltage VSS, and a controlterminal configured to receive a switch signal XSWG. The switch signalSWG and the switch signal XSWG have opposite phases. The transistor T11includes a first terminal coupled to a data voltage input terminal IN1,a second terminal coupled to a data line L3, and a control terminal. Thetransistor T12 includes a first terminal coupled to the control terminalof the transistor T11, a second terminal configured to receive a resetsignal MUX_L1, and a control terminal configured to receive a switchsignal XSWG. The capacitor C3 includes a first terminal coupled to boththe second terminal of the transistor T9 and the first terminal of thetransistor T10, and a second terminal coupled to both the controlterminal of the transistor T1 and the first terminal of the transistorT12. The transistor T13 includes a first terminal configured to receivea system voltage VDD, a second terminal, and a control terminalconfigured to receive a switch signal SWB. The transistor T14 includes afirst terminal coupled to the second terminal of the transistor T13, asecond terminal configured to receive a system voltage VSS, and acontrol terminal configured to receive a switch signal XSWB. The switchsignal SWB and the switch signal XSWB have opposite phases. Thetransistor T15 includes a first terminal coupled to a data voltage inputterminal IN1, a second terminal coupled to a data line L4, and a controlterminal. The transistor T16 includes a first terminal coupled to thecontrol terminal of the transistor T15, a second terminal configured toreceive a reset signal MUX_L1, and a control terminal configured toreceive a switch signal XSWB. The capacitor C4 includes a first terminalcoupled to both the second terminal of the transistor T13 and the firstterminal of the transistor T14, and a second terminal coupled to boththe control terminal of the transistor T15 and the first terminal of thetransistor T16. The transistor T17 includes a first terminal configuredto receive a system voltage VDD, a second terminal, and a controlterminal configured to receive a switch signal SWG. The transistor T18includes a first terminal coupled to the second terminal of thetransistor T17, a second terminal configured to receive a system voltageVSS, and a control terminal configured to receive a switch signal XSWG.The transistor T19 includes a first terminal coupled to a data voltageinput terminal IN2, a second terminal coupled to a data line L5, and acontrol terminal. The transistor T20 includes a first terminal coupledto the control terminal of the transistor T19, a second terminalconfigured to receive a reset signal MUX_L2, and a control terminalconfigured to receive a switch signal XSWG. The capacitor C5 includes afirst terminal coupled to both the second terminal of the transistor T17and the first terminal of the transistor T18, and a second terminalcoupled to both the control terminal of the transistor T19 and the firstterminal of the transistor T20. The transistor T21 includes a firstterminal configured to receive a system voltage VDD, a second terminal,and a control terminal configured to receive a switch signal SWB. Thetransistor T22 includes a first terminal coupled to the second terminalof the transistor T21, a second terminal configured to receive a systemvoltage VSS, and a control terminal configured to receive a switchsignal XSWB. The transistor T23 includes a first terminal coupled to thedata voltage input terminal IN2, a second terminal coupled to a dataline L6, and a control terminal. The transistor T24 includes a firstterminal coupled to the control terminal of the transistor T23, a secondterminal configured to receive the reset signal MUX_L2, and a controlterminal configured to receive the switch signal XSWB. The capacitor C6includes a first terminal coupled to both the second terminal of thetransistor T21 and the first terminal of the transistor T22, and asecond terminal coupled to both the control terminal of the transistorT23 and the first terminal of the transistor T24.

In this embodiment, the transistors T1 to T24 in FIG. 12 are all NMOStransistors. The operation manner of the transistors T9 to T12 and thecapacitor C3 of the driving unit 110 is similar to that of thetransistors T1 to T4 and the capacitor C1; and the operation manner ofthe transistors T17 to T20 and the capacitor C5 of the driving unit 120is similar to that of the transistors T5 to T8 and the capacitor C2.What is different is that the operations of the transistors T1 to T4 andthe capacitor C1 and the operations of the transistors T5 to T8 and thecapacitor C2 are controlled by the switch signals SWR and XSWR, whereasthe operations of the transistors T9 to T12 and the capacitor C3 and theoperations of the transistors T17 to T20 and the capacitor C5 arecontrolled by the switch signals SWG and XSWG instead. The rest of theoperation manners remain the same. As shown in FIG. 3, the switchsignals SWG and XSWG merely slightly lag behind the switch signals SWRand XSWR in terms of the time sequence, and the switch signals SWR andSWG are at the gate potential VGH at different times. Therefore, boththe operation manners of the transistors T9 to T12 and the capacitor C3of the driving unit 110 and of the transistors T17 to T20 and thecapacitor C5 of the driving unit 120 can be inferred by referring to theaforementioned operation manner of the transistors T1 to T4 and thecapacitor C1 and the aforementioned operation manner of the transistorsT5 to T8 and the capacitor C2. Details are not described again herein.

Likewise, the operation manner of the transistors T13 to T16 and thecapacitor C4 of the driving unit 110 is similar to that of thetransistors T1 to T4 and the capacitor C1; and the operation manner ofthe transistors T21 to T24 and the capacitor C6 of the driving unit 120is similar to that of the transistors T5 to T8 and the capacitor C2.What is different is that the operations of the transistors T1 to T4 andthe capacitor C1 and the operations of the transistors T5 to T8 and thecapacitor C2 are controlled by the switch signals SWR and XSWR, whereasthe operations of the transistors T13 to T16 and the capacitor C4 andthe operations of the transistors T21 to T24 and the capacitor C6 arecontrolled by the switch signals SWB and XSWB instead. The rest of theoperation manners remain the same. As shown in FIG. 3, the switchsignals SWB and XSWB merely slightly lag behind the switch signals SWRand XSWR in terms of the time sequence, and the switch signals SWR, SWG,and SWB are at the gate potential VGH at different times. Therefore,both the operation manners of the transistors T13 to T16 and thecapacitor C4 of the driving unit 110 and of the transistors T21 to T24and the capacitor C6 of the driving unit 120 can be inferred byreferring to the aforementioned operation manner of the transistors T1to T4 and the capacitor C1 and the aforementioned operation manner ofthe transistors T5 to T8 and the capacitor C2. Details are not describedagain herein.

In an embodiment of the present invention, the transistors T1 to T24 inFIG. 12 may be implemented by using PMOS transistors instead. As shownin FIG. 13, a circuit diagram of two driving units 110 and 120 forimplementing the multiplexer in FIG. 1 according to another embodimentof the present invention, wherein the transistors T1 to T24 in FIG. 12are implemented by using PMOS transistors instead in FIG. 13. Toaccommodate the changes of using PMOS transistors in implementing thetransistors T1 to T24, the waveforms of the switch signals SWR, SWG,SWB, XSWR, XSWG, and XSWB and the waveforms of the reset signals MUX_L1and MUX_L2 should be changed accordingly. In other words, the waveformsof the switch signals SWR, SWG, SWB, XSWR, XSWG, and XSWB are as shownin FIG. 7, and the waveforms of the reset signals MUX_L1 and MUX_L2 areas shown in FIG. 8.

In an embodiment of the present invention, the driving unit 110 and thedriving unit 120 in FIG. 12 may be integrated with a cell testing (CT)circuit of the display 200. Please refer to FIG. 14. FIG. 14 is acircuit diagram of two driving units 110 and 120 for implementing themultiplexer in FIG. 1 according to another embodiment of the presentinvention. Compared with the driving units 110 and 120 in FIG. 12, thedriving unit 110 in FIG. 14 further includes a transistor T25, and thedriving unit 120 in FIG. 14 further includes a transistor T26. Both thetransistors T25 and T26 are NMOS transistors. The transistor T25includes a first terminal configured to receive the switch signal SWR, asecond terminal coupled to the data line L1, and a control terminalconfigured to receive the test control signal CT. The transistor T26includes a first terminal configured to receive the switch signal SWR, asecond terminal coupled to the data line L2, and a control terminalconfigured to receive the test control signal CT. When a cell testing isperformed on the display 200, the electric potential of the test controlsignal CT is increased to a high electric potential, so that thetransistors T25 and T26 are turned on to transmit the switch signal SWRto the data lines L1 and L2. Meanwhile, the transistors T4 and T8 areturned on because of the switch signal XSWR, such that the transistorsT3 and T7 are turned off because the biases of the reset signals MUX_L1and MUX_L2 are being applied to the gates thereof; and during a normalperiod in which a cell testing is not performed, the electric potentialof the test control signal CT is a low electric potential, so that thetransistors T25 and T26 are not turned on. In this way, when a celltesting is performed on the display 200, the switch signal SWR is usedas a pixel voltage signal, to update the gray level of the sub-pixels ofthe display 200.

In another embodiment of the present invention, the driving unit 110 inFIG. 14 further includes transistors T25, T27, and T28, and the drivingunit 120 in FIG. 14 further includes T26, T29, and T30. The transistorsT25 to T30 are all NMOS transistors. The transistor T25 includes a firstterminal configured to receive the switch signal SWR, a second terminalcoupled to the data line L1, and a control terminal configured toreceive a test control signal CT. The transistor T26 includes a firstterminal configured to receive the switch signal SWR, a second terminalcoupled to the data line L2, and a control terminal configured toreceive the test control signal CT. The transistor T27 includes a firstterminal configured to receive the switch signal SWG, a second terminalcoupled to a data line L3, and a control terminal configured to receivethe test control signal CT. The transistor T28 includes a first terminalconfigured to receive the switch signal SWB, a second terminal coupledto a data line L4, and a control terminal configured to receive the testcontrol signal CT. The transistor T29 includes a first terminalconfigured to receive the switch signal SWG, a second terminal coupledto a data line L5, and a control terminal configured to receive the testcontrol signal CT. The transistor T30 includes a first terminalconfigured to receive the switch signal SWB, a second terminal coupledto a data line L6, and a control terminal configured to receive the testcontrol signal CT. When a cell testing is performed on the display 200,the electric potential of the test control signal CT is increased to ahigh electric potential, so that the transistors T13 and T18 are turnedon to transmit the switch signal SWR to the data lines L1 and L2,transmit the switch signal SWG to the data lines L3 and L4, and transmitthe switch signal SWB to the data lines L5 and L6. In other words, whena cell testing is performed on the display 200, the switch signals SWR,SWG, and SWB are used as pixel voltage signals, to update the gray levelof the sub-pixels of the display 200. Likewise, when a cell testing isperformed on the display 200, data voltage input terminals IN1 and IN2stop inputting the pixel voltage signals S1 and S2, so that anyinterference to the cell testing process can be avoided.

In an embodiment of the present invention, the transistors T1 to T30 inFIG. 14 may be implemented by using PMOS transistors instead. Withreference to FIG. 15, FIG. 15 is a circuit diagram of two driving units110 and 120 for implementing the multiplexer in FIG. 1 according toanother embodiment of the present invention. The difference between thedriving units 110 and 120 in FIG. 15 and those in FIG. 14 is that allthe transistors, T1 to T30, of the driving units 110 and 120 in FIG. 15are PMOS transistors. When a cell testing is performed on the display200, the electric potential of the test control signal CT is increasedto a low electric potential, such that the transistors T13 and T18 areturned on, so as to transmit the switch signal SWR to the data lines L1and L2, transmit the switch signal SWG to the data lines L3 and L4, andtransmit the switch signal SWB to the data lines L5 and L6.

Through the above embodiments, two different reset signals are appliedto the multiplexer of the present invention to increase an absolutevalue of a voltage difference between a gate and a drain of a transistorfor driving a data line, thereby strengthening the driving capability ofthe transistor. In this way, no matter whether the transistors of themultiplexer are NMOS transistors or PMOS transistors, the multiplexerhas a sufficient driving capability for data lines and sub-pixels.Therefore, the transistors of the multiplexer can all beN-Metal-Oxide-Semiconductor transistors or P-Metal-Oxide-Semiconductortransistors, thereby simplifying the process of manufacturing themultiplexer and/or a panel and improving the competitiveness of productsthereof.

The above description only provides preferred embodiments of the presentinvention, and all equivalent changes and modifications made accordingto the claims of the present invention falls within the scope of thepresent invention.

What is claimed is:
 1. A multiplexer, comprising: a plurality of firstdriving units, each of the first driving units comprising: a first datavoltage input terminal, for receiving a first pixel voltage signal; afirst transistor, comprising: a first terminal, for receiving a firstsystem voltage; a second terminal; and a control terminal, for receivinga first switch signal; a second transistor, comprising: a firstterminal, coupled to the second terminal of the first transistor; asecond terminal, for receiving a second system voltage; and a controlterminal, for receiving a second switch signal, wherein the first switchsignal and the second switch signal have opposite phases; a thirdtransistor, comprising: a first terminal, coupled to the first datavoltage input terminal; a second terminal, coupled to a first data line;and a control terminal; a fourth transistor, comprising: a firstterminal, coupled to the control terminal of the third transistor; asecond terminal, for receiving a first reset signal; and a controlterminal, for receiving the second switch signal; and a first capacitor,comprising: a first terminal, coupled to the second terminal of thefirst transistor and the first terminal of the second transistor; and asecond terminal, coupled to the control terminal of the third transistorand the first terminal of the fourth transistor; and a plurality ofsecond driving units, each of the second driving units comprising: asecond data voltage input terminal, for receiving a second pixel voltagesignal, wherein the first pixel voltage signal and the second pixelvoltage signal have opposite polarities; a fifth transistor, comprising:a first terminal, for receiving the first system voltage; a secondterminal; and a control terminal, for receiving the first switch signal;a sixth transistor, comprising: a first terminal, coupled to the secondterminal of the fifth transistor; a second terminal, for receiving thesecond system voltage; and a control terminal, for receiving the secondswitch signal; a seventh transistor, comprising: a first terminal,coupled to the second data voltage input terminal; a second terminal,coupled to a second data line; and a control terminal; an eighthtransistor, comprising: a first terminal, coupled to the controlterminal of the seventh transistor; a second terminal, for receiving asecond reset signal; and a control terminal, for receiving the secondswitch signal; and a second capacitor, comprising: a first terminal,coupled to the second terminal of the fifth transistor and the firstterminal of the sixth transistor; and a second terminal, coupled to thecontrol terminal of the seventh transistor and the first terminal of theeighth transistor; wherein the first reset signal is different from thesecond reset signal.
 2. The multiplexer according to claim 1, whereineach of the first driving units further comprises: a ninth transistor,comprising: a first terminal, for receiving the first system voltage; asecond terminal; and a control terminal, for receiving a third switchsignal; a tenth transistor, comprising: a first terminal, coupled to thesecond terminal of the ninth transistor; a second terminal, forreceiving the second system voltage; and a control terminal, forreceiving a fourth switch signal; wherein the third switch signal andthe fourth switch signal have opposite phases; an eleventh transistor,comprising: a first terminal, coupled to the first data voltage inputterminal; a second terminal, coupled to a third data line; and a controlterminal; a twelfth transistor, comprising: a first terminal, coupled tothe control terminal of the eleventh transistor; a second terminal, forreceiving the first reset signal; and a control terminal, for receivingthe fourth switch signal; a third capacitor, comprising: a firstterminal, coupled to the second terminal of the ninth transistor and thefirst terminal of the tenth transistor; and a second terminal, coupledto the control terminal of the eleventh transistor and the firstterminal of the twelfth transistor; a thirteenth transistor, comprising:a first terminal, for receiving the first system voltage; a secondterminal; and a control terminal, for receiving a fifth switch signal; afourteenth transistor, comprising: a first terminal, coupled to thesecond terminal of the thirteenth transistor; a second terminal, forreceiving the second system voltage; and a control terminal, forreceiving a sixth switch signal; wherein the fifth switch signal and thesixth switch signal have opposite phases; a fifteenth transistor,comprising: a first terminal, coupled to the first data voltage inputterminal; a second terminal, coupled to a fourth data line; and acontrol terminal; a sixteenth transistor, comprising: a first terminal,coupled to the control terminal of the fifteenth transistor; a secondterminal, for receiving the first reset signal; and a control terminal,for receiving the sixth switch signal; and a fourth capacitor,comprising: a first terminal, coupled to the second terminal of thethirteenth transistor and the first terminal of the fourteenthtransistor; and a second terminal, coupled to the control terminal ofthe fifteenth transistor and the first terminal of the sixteenthtransistor; each of the second driving units further comprises: aseventeenth transistor, comprising: a first terminal, for receiving thefirst system voltage; a second terminal; and a control terminal, forreceiving the third switch signal; an eighteenth transistor, comprising:a first terminal, coupled to the second terminal of the seventeenthtransistor; a second terminal, for receiving the second system voltage;and a control terminal, for receiving the fourth switch signal; anineteenth transistor, comprising: a first terminal, coupled to thesecond data voltage input terminal; a second terminal, coupled to afifth data line; and a control terminal; a twentieth transistor,comprising: a first terminal, coupled to the control terminal of thenineteenth transistor; a second terminal, for receiving the second resetsignal; and a control terminal, for receiving the fourth switch signal;a fifth capacitor, comprising: a first terminal, coupled to the secondterminal of the seventeenth transistor and the first terminal of theeighteenth transistor; and a second terminal, coupled to the controlterminal of the nineteenth transistor and the first terminal of thetwentieth transistor; a twenty-first transistor, comprising: a firstterminal, for receiving the first system voltage; a second terminal; anda control terminal, for receiving the fifth switch signal; atwenty-second transistor, comprising: a first terminal, coupled to thesecond terminal of the twenty-first transistor; a second terminal, forreceiving the second system voltage; and a control terminal, forreceiving the sixth switch signal; a twenty-third transistor,comprising: a first terminal, coupled to the second data voltage inputterminal; a second terminal, coupled to a sixth data line; and a controlterminal; a twenty-fourth transistor, comprising: a first terminal,coupled to the control terminal of the twenty-third transistor; a secondterminal for receiving the second reset signal; and a control terminal,for receiving the sixth switch signal; and a sixth capacitor,comprising: a first terminal, coupled to the second terminal of thetwenty-first transistor and the first terminal of the twenty-secondtransistor; and a second terminal, coupled to the control terminal ofthe twenty-third transistor and the first terminal of the twenty-fourthtransistor.
 3. The multiplexer according to claim 1, wherein each of thefirst driving units further comprises: a twenty-fifth transistor,comprising: a first terminal, for receiving the first switch signal; asecond terminal, coupled to the first data line; and a control terminal,for receiving a test control signal; and each of the second drivingunits further comprises: a twenty-sixth transistor, comprising: a firstterminal, for receiving the first switch signal; a second terminal,coupled to the second data line; and a control terminal, for receivingthe test control signal.
 4. The multiplexer according to claim 2,wherein each of the first driving units further comprises: atwenty-fifth transistor, comprising: a first terminal, for receiving thefirst switch signal; a second terminal, coupled to the first data line;and a control terminal, for receiving a test control signal; atwenty-seventh transistor, comprising: a first terminal, for receivingthe third switch signal; a second terminal, coupled to the third dataline; and a control terminal, for receiving the test control signal; anda twenty-eighth transistor, comprising: a first terminal, for receivingthe fifth switch signal; a second terminal, coupled to the fourth dataline; and a control terminal, for receiving the test control signal; andeach of the second driving units further comprises: a twenty-sixthtransistor, comprising: a first terminal, for receiving the first switchsignal; a second terminal, coupled to the second data line; and acontrol terminal, for receiving the test control signal; a twenty-ninthtransistor, comprising: a first terminal, for receiving the third switchsignal; a second terminal, coupled to the fifth data line; and a controlterminal, for receiving the test control signal; and a thirtiethtransistor, comprising: a first terminal, for receiving the fifth switchsignal; a second terminal, coupled to the sixth data line; and a controlterminal, for receiving the test control signal.
 5. The multiplexeraccording to claim 1, wherein all the transistors of the first drivingunit and the second driving unit are P-type metal-oxide-semiconductortransistors.
 6. A method for driving the multiplexer according to claim1, wherein the multiplexer is used for a liquid crystal display, and allthe transistors of the first driving unit and the second driving unitare P-type metal-oxide-semiconductor transistors, the method comprising:during the n^(th) frame period of the liquid crystal display, making thefirst pixel voltage signal to have a first polarity, making the secondpixel voltage signal to have a second polarity, making the first resetsignal to have an electric potential at a first reset level, and makingthe second reset signal to have an electric potential at a second resetlevel, wherein n is a positive integer, the first polarity is differentfrom the second polarity, and the second reset level is higher than thefirst reset level; and during the (n+1)^(th) frame period of the liquidcrystal display, making the first pixel voltage signal to have thesecond polarity, making the second pixel voltage signal to have thefirst polarity, making the first reset signal to have the electricpotential at the second reset level, and making the second reset signalto have the electric potential at the first reset level.
 7. The methodaccording to claim 6, wherein the method further comprises: setting thefirst reset level to be higher than a ground potential.
 8. The methodaccording to claim 7, wherein the method further comprises: making avoltage difference between the first reset level and the groundpotential to be equal to a preset voltage difference, wherein the presetvoltage difference is between Vth+0.5 V and Vth−0.5 V, and Vth being anaverage value of absolute values of threshold voltages of all thetransistors in the first driving unit and the second driving unit. 9.The method according to claim 6, wherein the first switch signal and thesecond switch signal are respective square waves having electricpotentials switched between a gate high potential and a gate lowpotential, and the second reset level is equal to the gate highpotential.